Variable-area flowmeter with removable metering tube

ABSTRACT

A flowmeter of the rotameter type in which a variable-area meter tube is supported between the fittings of inlet and outlet assemblies. In order to make possible removal of the tube for cleaning, repair or replacement purposes, the fitting on the outlet assembly is provided with a retractable adapter which normally engages the top end of the tube and which may be fitted out of engagement therewith to permit an ejector spring to push the tube out of the flowmeter frame.

[54] VARIABLE-AREA FLOWMETER WITH REMOVABLE METERING TUBE 2/ 1 96bBusillo; ..73/209 Primary Examiner-Richard C. Queisser [72] Inventor.lgarold W. Metzger, WlllOW Grove, Assistant Examinepdohn P. BeauchampAttorney-Michael Ebert [73] Assignee: Fischer 8: Porter Company,Warminster, Pa. v 7 ABSTRACT 2 Fil d; hm 20, 7 A flowmeter of therotameter type in which a variable- 7 area meter tube is supportedbetween the fittings of PP 108,053 inlet and outlet assemblies. In orderto make possible I removal of the tube for cleaning, repair orreplacement purposes, the fitting on the outlet assembly is [52] US. Cl..73/209, 73/323 provided with a retractable adapt which normally [51]Int.Cl ..G0lf l/00 engages the top end of the tube and which may be [58]Field of Search ..73/209, 210, 323, 324 fitted out of engagementtherewith to permit an ejec tor spring to push the tube out of theflowmeter frame. [56] References Cited 8 Claims, 7 Drawing FiguresUNITED STATES PATENTS I 29 249 7 1 265 M26 2!!!9E%L;--,---'-- -13 29 i j,sz Z EA 1 4 Z41 i 554 ll 5 a 7/ |z% Q 7 PATENTEDSEP 19 m2 3.691.835

SHEET 2 0F 2 INVENTORI A Trap/YE) This'inventionrelates generally toaflowmeter of the rotameter type having a variable-area tube, and moreparticularly to a rotameter in which the meter tube may be readilyremoved without disassembling the flowme- IBI'.

In the usual type of rotameter a weighted plummet or,

float contained in an upright tapered tube is raised to a position ofequilibrium between the downward force of the float and the upward forceofthe fluid flowing past the float throughthe annular orificesurrounding the float. The term rotameter was derived from the fact thatplummets originally had slots therein to impart a rotational force forthe purpose of centering and sta bilizing the float. The present trend,however, is toward guided,'non-rotating floats.

In one well-known commercial form of rotameter, such as that disclosedin my prior U.S. Pat. No. 3,342,068, the flowmeter is provided with atube having a tapered bore affording a variable cross-sectional area.The float disposed in the bore assumes a vertical position depending onthe rate of fluid flow, which may be liquid or gas. The verticalposition of the float is indicated along a calibrated scale on the frontof the tube.

Because the meter tube having atapered bore is made of glass and isrelatively fragile, the tube is supported ina frame or mounting adaptedto protect the tube against stresses as well as to effect tight sealing.

which may be manufactured andsold at relatively low .COSt.

Briefly stated, these objects are accomplished in a flowmeter having ameter tube supported in a frame between an inlet and an outlet assembly,the outlet assembly including an outlet fitting provided with aretractable outlet adapter to receive the top end of the tube and meansto withdraw the adapter from the top With a variable-area flowmeter, onemust be able to remove the meter tube in order to clean itas well as tofacilitate inspection and replacement of parts. Moreover, one'may alsowish to replace a meter tube of a given bore sizejwith another tubehaving a different bore size to afford a different measurement range.Since the flowmeter components, with the exception of the tubes, areotherwise the same, it is more economical, when a-different meteringscale is required, to merely replace the tube rather than to provide asecond flowmeter in which all components, except for the tube, duplicatethose of the first flowmeter.

With existing flowmeter designs, the ability to remove a, meter tube andto replace the tube with another tube of the same length but of adifferent range is complicated by the fact that to carry out thisoperation, the meter must be at least partially dismantled. This isundesirable from the practical standpoint, for it involves not onlytime, but some degree of slcill and care as well as the use of specialtools.

SUMMARY OF THE INVENTION In view of the foregoing, it is the main objectof this invention to provide a rotameter having a variable-area tubewhich may be readily removed and replaced without in any waydisassembling the meter and without the use of tools.

More specifically, it is an object of the invention to provide acompact, rectangular-shaped, variable-area flowmeter including aflat-faced, glass metering tube which essentially fills the opening inthe meter frame and can be easily removed therefrom.

Also an object of the invention is to provide aflowmeter which operatesreliably and accurately and end whereby an ejector is then able to pushthe tube out of the frame therefor;

. OUTLINEOF THE DRAWING FIG. 5 separately shows the lifter element forthe adapter included in the meter;

FIG. 6 is a partial front view of the meter; and

FIG. 7 illustrates the ejection of the meter tube when the adapter islifted.

DESCRIPTION OF THE INVENTION Referring now to the drawing, there isshown a flowmeter in accordance with the invention, which includes anopen-ended, transparent meter tube 10, preferably fabricated ofborosilicate glass, having a precisionmolded tapered bore 11 extendinglongitudinally therein, to provide a variable area to accommodate afloat l2. v f

In practice, each flowmeter may be provided with a set ofinterchangeable flowmeter tubes, all of them having the same exteriorform and dimensions, but with bores of different nominal sizes, say fromone-sixteenth to one-quarter inch or more, to afford different measuringranges.

Float 12 preferably consists of a spherical ball of stainless steel orother non-corrodible material. The

float, under fluid pressure, is raised from a lower stop 13 in the formof a helical spring inserted in the bottom of the tube, to an upperstop.l4 of similar form inserted at the top of the tube. Tube 10 isformed with a flat face 10A, along which indicia are etched or otherwiseformed to define a meter scale. Secured to the rear of the tube is adecal I5 having a white or reflective surface to facilitate reading thefront scale.

The bottom end of the tube is seated on the shoulder of an inlet adapter16 provided with an O ring 17 to effect a fluid-tightseal. Adapter 16 isreceived in a well formed in an'inlet fitting, generally designated bynumeral 18, the fitting including a nipple 18A to which an inlet pipemay be coupled for supplying fluid to the meter. Fluid flow betweeninlet nipple 18A and inlet adapter 16 is controlled by aneedle valve 19whose axial position in the fluid passage is varied by means of a knob20, the valve plug engaging seat 21.

The top end of the tube It). is seated on the shoulder of a retractableoutlet adapter 22 which is slidable tube with passage."

' within an outlet fitting 23 The shoulder of adapter 22' is providedwith an O ring 24 to effect'a fluid-tight seal between the upper end oftube l0 and the outlet adapter. The sliding adapter also includes asecond In order to release tube,10 for purposes of cleaning,

retracted. by means of a lifter element,- generally I designated bynumeral 27. As shown separately in FIG.

5, lifter element 27 is provided'with an opening 27A to accommodateoutlet adap ter 22,,one end of the element being. bent to define ahandle 278 which protrudes'from the frontend of themeter. The other endof element 27 has a hole 27C therein, making it possible to mount thisend on a retaining screw 28 threaded into. the body of outlet fitting23. In practice,

thehandle or actuating member of thelifter'may be made inaccessibleexcept by means of a simple tool, to avoid unauthorized or accidentaloperation of the lifter. i

J Also mountedfon screw 28 is an ejector spring,

generally designatedby numeral 29,'which is cut-and bent to define pairofspaced'arms'29A and 29B'for embracing the-rear side of meter tube 10.The ejector is biased so that when'the outlet adapter is'withdrawninspection of replacement, the outlet adapter 22 is fromthe upper end oftube 10 by raising lifter. 27, the

ejector then pushes the tube forward,'as shown in FIG.

' tube lS transparent and is provided with a flat front face havingindicia inscribed thereon.

I, to'facilitate removal and replacement, 1. The. frame of .the meter isformed by a pairof side plates. 30 -.add. 31 and a back cover 32extending between the inlet and outlet fittings, the front of the framebeing open to expose the meter tube and to provide access thereto.Nipple 18A of the inlet fitting projects through a first aperture incover 32, while nipple 23A of the outlet fitting projects through asecond aperture in cover 32, the cover maintaining a fixed,

' spaced relationship between the two fittings.

While there has been shown and described a preferred embodiment ofvariable-area flowmeter with removable metering tube in accordance withthe invention, it will be understood that many changes and modificationsmay be made therein without, however, departing from the essentialspirit thereof. For example, retraction of the outlet adapter may beeffected by a knob-operated .screwcoupled to the adapter and arranged tomove the adapter toward or away from the to the-meter, all one needdoistofirstraise the outlet adapter and then seat the bottom endof thetube on the inlet adapter as well asto press i n the tube against theejector to cause it to assume a vertical position, a which point theoutlet adaptermay be brought down on the top end of the tube."

It is also to .beunderstood that the invention is not limited to aretractable outlet adapter, for in practice, the inlet adaptermay bemaderetractable, in which event the outlet adapter is fixed. lclaim: fl. A flowmeter of the rotamet'er type comprising: A. an open-ended tubehaving abore extending lon- .gitudinally therein whose cross-sectionvaries v along its lengthand is adapted to accommodate a 'float forvertical movement therein as a function of flowrate,' BQan inletassemblyincluding an inletfitting pro 'vided with a inlet adapter for receivingthe bottom end of the tube for supplying thereto a fluid to be measured,-C. An outlet assembly including an outlet fitting pro; -vided with anoutlet adapter. for receiving the top endjof the'tube'fordischargingfluidtherefrom,

D.-m e ans-to maintain-a fixed relationship between said inlet fittingand saidoutlet fitting, oneof said adapters being retractable within itsassociated fitting and being normally extended to engage the related endofthe tube,

E. means coupled to said retractable adapter to disengage it, from therelated end of the tube, and

F. means coupled to said tube to eject the tube when said retractableadapter is disengaged. 2. Aflowmeter as set forth in claim 1, whereinsaid inlet adapter is fixed and said outlet adapter is retractable torender it withdrawable.

' 3. A flowmeter'as set forth in claim 1 wherein said 4. Aflowmeter asset forth in claim 1, wherein said inlet assembly includes a needlevalve to control fluid flow into said tube.

5. A flowmeter as set forth in claim 2, wherein said outlet assemblyincludes a helical spring urging said outlet adaptertoward the top endof said tube, and said means to disengage said retractable outletadapter is constituted by manually-operated lifter engaging said outletadapter to withdraw it from engagement with said top end.

6. A flowmeter as set forth in claim 5, wherein said lifter is providedwith a handle-projecting from the front end of themeter.

7. A flowmeter as set forth in claim 2, wherein said ejector means isconstituted by a flat spring having a pair of arms embracing' the'surfaceof said tube adjacent the top end thereof.

8. A flowmeter as set forth in claim 1 further including a frameconstituted by a pair of side plates and a back cover extending betweensaid inlet and outletassemblies, the front end of said frame being opento expose said tube. =0:

1. A flowmeter of the rotameter type comprising: A. an open-ended tubehaving a bore extending longitudinally therein whose cross-sectionvaries along its length and is adapted to accommodate a float forvertical movement therein as a function of flow rate, B. an inletassembly including an inlet fitting provided with a inlet adapter forreceiving the bottom end of the tube for supplying thereto a fluid to bemeasured, C. An outlet assembly including an outlet fitting providedwith an outlet adapter for receiving the top end of the tube fordischarging fluid therefrom, D. means to maintain a fixed relationshipbetween said inlet fitting and said outlet fitting, one of said adaptersbeing retractable within its associated fitting and being normallyextended to engage the related end of the tube, E. means coupled to saidretractable adapter to disengage it from the related end of the tube,and F. means coupled to said tube to eject the tube when saidretractable adapter is disengaged.
 2. A flowmeter as set forth in claim1, wherein said inlet adapter is fixed and said outlet aDapter isretractable to render it withdrawable.
 3. A flowmeter as set forth inclaim 1 wherein said tube is transparent and is provided with a flatfront face having indicia inscribed thereon.
 4. A flowmeter as set forthin claim 1, wherein said inlet assembly includes a needle valve tocontrol fluid flow into said tube.
 5. A flowmeter as set forth in claim2, wherein said outlet assembly includes a helical spring urging saidoutlet adapter toward the top end of said tube, and said means todisengage said retractable outlet adapter is constituted bymanually-operated lifter engaging said outlet adapter to withdraw itfrom engagement with said top end.
 6. A flowmeter as set forth in claim5, wherein said lifter is provided with a handle projecting from thefront end of the meter.
 7. A flowmeter as set forth in claim 2, whereinsaid ejector means is constituted by a flat spring having a pair of armsembracing the surface of said tube adjacent the top end thereof.
 8. Aflowmeter as set forth in claim 1, further including a frame constitutedby a pair of side plates and a back cover extending between said inletand outlet assemblies, the front end of said frame being open to exposesaid tube.